1. Technical Field
This patent pertains to the field of cosmetics and skin care products, including moisture cream, moisture lotions, glycolic creams, glycolic lotions, shampoos, cleansers, colored makeup foundation, colored makeup powder, and colored makeup concealers.
2. Prior Art
Cosmetics have been in use since Biblical times. They served not only to soothe the skin and provide relief from minor irritations, but also to cover skin defects and to enhance beauty.
The physician's credo to "first, do no harm", however, is of considerable importance concerning skin care products. If aesthetic concerns were the only consideration with respect to cosmetics, another cosmetic line would certainly not be necessary.
However, potential problems exist with all cosmetics and skin care products currently on the market. Acne cosmetica is a problem seen all too frequently by the dermatologist. Comedogenicity is another major concern. Chemicals such as Isopropyl Myristate, Steareth 16, Isopropyl Palmitate, Cetyl Alcohol, Stearic Acid, Stearic Acid, Laureth-4, and many others are major causes of acne among users and yet are still found in many current cosmetic products. Oils or petroleum products such as mineral oil, Vitamin E, Jojoba oil or petrolatum cause severe acne in many patients. As a dermatologist and dermatologic surgeon I have spent the past 20 years treating the resultant acne scarring with chemical peeling, dermabrasion, dermal grafting, and laser surgery. I therefore have sought to invent a line of skin care products that would not initiate acne and hence, would protect patients from the need for correction of the disfiguring sequelae.
Many chemicals, though not comedogenic, frequently cause contact dermatitis. Indeed, many products on the market contain ingredients that are included in the North American Contact Dermatitis Society's standard patch test tray of 20 allergens. Products such as Cetyl Alcohol, Stearyl Alcohol, Lanolin (which aggravates eczema or atopic dermatitis), Propylene Glycol, Laureth-4, Steareth-16, Vitamin E, and other alcohols are frequent causes of contact dermatitis and irritant dermatitis. Imidazolidinyl urea and Quaternium-15 are releasers of formaldehyde, the chemical responsible for some of the most severe cases of contact dermatitis seen by a dermatologist. Fragrances, including Balsam of Peru, Cinammic Alcohol and Aldehyde and numerous natural plant products and extracts are the most common causes of contact dermatitis originating from cosmetics. Many patients also find perfumes offensive. No product can, of course, be "non-allergenic"--even water can cause a form of hives known as aquagenic urticaria.
However, it is possible to create a line that is as hypoallergenic as possible by avoiding the use of chemicals listed in the master list of comedogenic/irritating chemicals. Such a list has been detailed by James E. Fulton, Jr., M.D. and is entitled "Comedogenicity and Irritancy of Commonly Used Ingredients in Skin Care Products". (Journal of the Society of Cosmetic Chemists, Vol. 40, pps 321-333, November 1989).
One important point for discussion and consideration is the concentration of such comedogenic/irritating chemicals in the actual marketed products. Fulton, however, makes the key point that "The major offenders, such as Isopropyl Myristate, Acetylated Lanolin Alcohol and Lauric Acid derivatives such as Laureth-4 should be used with caution in skin care products. We are not convinced of the statement that lower concentrations of these compounds can be safely used with no comedogenic consequences. Human skin studies have been used to give that statement credence, but the back skin of human volunteers is relatively insensitive. However, when the rabbit ear assay is positive, but the human back skin results are negative after only 8 weeks exposure, the results from the rabbit ear assay should not be dismissed. The reaction may take longer or the back skin may not be the ideal testing substance."
Therefore, avoidance of such disease--aggravating compounds would seem to be a priority with cosmetic manufacturers. One frequently encounters claims of non-comedogenicity, non-irritancy and hypoallergenicity among cosmetic products currently on the shelf.
However, a quick review of the ingredient list from all currently marketed products always reveals one or more major offenders present on Fulton's list. It is quite possible that the test sample required for acnegenicity claims (25 patients) or allergenicity claims (50 to 200 patients) may be too small, however, to detect problems that we dermatologists frequently see among larger or more varied patient populations.
______________________________________ TABLE OF COMEDOGENICITY RATINGS AND IRRITANCY RATINGS AMONG COMMONLY USED COSMETIC INGREDIENTS COMEDOGENICITY IRRITANCY COMPONENTS RATING RATING ______________________________________ Petrolalum 5 0 Cetyl Alcohol 2 2 Stearic Acid 2-3 0 Stearyl Alcohol 2 2 Lanolin Products 0-4 0-3 Triethanolamine 2 0 Fragrance 0 0-5+ Imidazolidinyl urea 0 0-5+ Quaternium-15 (formaldehyde 0 0-6+ releasers) Propylene Glycol 0 0-5+ Laureth-4 4 4 Steareth-16 5 1-3 Isopropyl Myristate 2-4 3 Isopropyl Palmitate 5 1 Oils 4 1-2 Dyes 1-3 1-2 Vitamin-E 0-3 0-3 Comedogenic or Irritating 1-5 1-5 Alcohols ______________________________________
Why, then, has a line such as mine never been formulated? One consideration is the ready availability of inexpensive chemicals such as Petrolatum or Mineral Oil. Another factor is the tendency to repeat endlessly minor variations of older formulas in existence for many years. Additionally, larger manufacturers may simply be able to afford to ignore the 1% to 2% of patients who develop acne or contact dermatitis, reasoning that a refund may be expeditious from the business sense. Finally, the restriction of an ingredient formulary to items rated "0" on Fulton's list greatly reduces the chemicals still available for inclusion in such a cosmetic line.
The increasing world wide prevalence of skin cancer, (basal cell carcinoma, squamous cell carcinoma and malignant melanoma) has led many formulators to include sunscreens in skin care products applied to exposed areas. The formulator must seek to employ ingredients providing adequate sun protection while avoiding comedogenicity and irritancy.
Alpha-hydroxy acids have been included in many cosmetics in recent years. These "fruit acids" have been found in numerous studies to increase synthesis of dermal collagen, decrease signs of aging and sun damage (including rhytides and dyspigmentation) and to provide mild keratolysis and desquamation. However, the clinical effect of these acids is directly dependent upon the degree of buffering, and resultant pH, of the acid in the cosmetic. Many products sold over the counter contain glycolic or other acids in concentrations so low, or a pH so high, as to render these acids ineffective for the purpose for which they were added. It takes a fine balancing act, and many evaluations by an experienced dermatologist, to arrive at a glycolic acid concentration which minimizes stinging and burning and yet has a pH low enough, and a concentration high enough, to exert a long-term clinical effect.
As a practicing dermatologist and dermatologic surgeon I feel that it is essential to design a product line that contains effective concentrations of pertinent chemicals while avoiding components known to be allergenic, irritating, acne causing, or comedogenic. Such a cosmetic line would prove to be aesthetically pleasing and yet avoid common clinical problems such as acne scarring, irritant dermatitis, photosensitivity, or permanent allergic contact sensitization.